Recoil inhibitor for prosthetic valve

ABSTRACT

A valve loading apparatus is provided for loading a crimped prosthetic valve into a lumen of a delivery system. The valve recoil adapter can counteract recoil of a compressed prosthetic valve, and maintain the valve at its desired crimp diameter. An integrated bioprosthesis/delivery system is provided for delivering a bioprosthesis to a target area within a body lumen is provided. The delivery system includes a valve covering member and a compressing member, which compresses the valve covering member to surround, hold, and/or compress the valve during delivery to the target area.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to commonly assigned U.S. provisionalpatent application No. 60/969,522 filed Aug. 31, 2007, which is herebyincorporated by reference in its entirety.

FIELD

The invention relates generally to delivery catheters and, moreparticularly, to a method and device for preparing a stented prostheticvalve for delivery into a patient's body.

BACKGROUND

A variety of prosthetic valves have been developed for replacingdefective native valves, such as an aortic heart valve, in a human body.Prosthetic valves typically include a valve structure mounted on a stentwhich is delivered to a treatment site via a percutaneouscatheterization technique. A stent is a generally cylindrical prosthesisintroduced into a lumen of a body vessel via a catheterizationtechnique. Stents may be self-expanding or balloon expandable.Balloon-expandable stents are typically crimped from an initial largediameter to a smaller diameter prior to advancement to a treatment sitein the body. Before crimping, a balloon expandable stent is typicallyplaced over an expandable balloon on a catheter shaft.

To properly position a balloon expandable stent on a delivery catheterover the expandable balloon, the stent must be smoothly and evenlycrimped to closely conform to the overall profile of the catheter andthe unexpanded balloon.

Despite the most careful and firm crimping, physical properties of thematerial used in manufacturing stents (some stainless steels, tantalum,platinum or platinum alloys, CoCr, MP35N or shape memory alloys such asNitinol™) allow a certain amount of “recoil” of the stent. That is, thestent tends to slightly open up from its crimped diameter once thecrimping force has been removed. In some instances, the stent diameterhas been shown to increase about 15% from its crimped diameter.

The enlarged recoil diameter increases the overall profile of theunderlying catheter and balloon. Thus, since the stented prostheticvalve is configured to be delivered percutaneously, in a less invasiveprocedure, a smaller device is beneficial.

SUMMARY

In one embodiment, a valve recoil inhibitor adapter is provided whichmay be attached onto a loader or delivery system component. The valverecoil adapter counteracts the stent recoil and maintains the overallvalve frame and device at its desired crimp diameter.

In another embodiment, a prosthesis assembly, including a bioprosthesisand a balloon catheter, is inserted into or covered with an over tube,which maintains the bioprosthesis in substantially a delivery diameterand prevents the bioprosthesis from recoiling.

In another embodiment, an integrated bioprosthesis/delivery system fordelivering a bioprosthesis to a target area within a body lumen isprovided. The delivery system includes a moveable cover and a slit tube,where the moveable cover is positioned over the slit tube in atelescoping arrangement. The delivery system encapsulates, holds, anddelivers the bioprosthesis to the target area.

In one embodiment, a valve loading apparatus for loading a crimpedprosthetic valve into a lumen of a delivery system is provided. Thevalve loading apparatus comprises a first portion, a second portion, anda transitional portion. The first portion is configured to receive acrimped prosthetic valve. The second portion is configured to be coupledto a distal end of the delivery system. The apparatus has an openingthat passes through the first, second, and transitional portions. Theopening has a first diameter at the first portion and a second diameterat the second portion, with the first diameter being larger than thesecond diameter. The transitional portion has a transitional diameterthat varies from the first diameter to the second diameter. When thecrimped valve is passed through the opening of the loading apparatus andinto the lumen of the delivery system, the crimped valve is radiallycompressed from a larger diameter to a smaller diameter.

In a specific implementation, the second portion has a third diametersection. The third diameter is larger than the second diameter. Thetransition from the second diameter to the third diameter forms a lip,and the lip is configured to abut the distal end of the delivery system.

In another specific implementation, the valve loading apparatus furthercomprises a first clamp portion and a second clamp portion, with thefirst and second clamp portions being separable from one another. Thefirst clamp portion forms a part of each of the first, second, andtransitional portions, and the second clamp portion forms the remainderof the first, second, and transitional portions. In another specificimplementation, the valve loading apparatus further comprises a pushingmember. The pushing member comprises a handle portion and one or moreextending portions, with the extending portions having a hollow centralarea and being sized to extend into the opening of the valve loadingapparatus to urge the crimped prosthetic valve through the opening ofthe valve loading apparatus. In another specific implementation, theextending portions of the pushing member comprise two or more annularlyspaced finger members.

In another embodiment, a method of loading a crimped prosthetic valveinto a lumen of a delivery system is provided. The method comprisescrimping a prosthetic valve on a balloon member of a balloon catheter.The method further comprises providing a loading apparatus, the loadingapparatus having a first section and a second section. The first sectionhas a first diameter and the second section has a second diameter. Thesecond diameter is smaller than the first diameter. The method furthercomprises introducing the crimped prosthetic valve into the firstsection, wherein at the time of introduction into the first section, thecrimped prosthetic valve has a diameter greater than the seconddiameter. The method further comprises passing the crimped prostheticvalve through the second section and into the lumen of the deliverysystem. The crimped prosthetic valve exits the second section with thecrimped prosthetic valve having a diameter that is equal to or less thanthe second diameter.

In a specific implementation, the method further comprises coupling thesecond section of the loading apparatus to a distal end of the deliverysystem. In another specific implementation, the method further comprisespassing the balloon member through an introducer sheath prior to priorto crimping the prosthetic valve on the balloon member. In anotherspecific implementation, the act of passing the crimped prosthetic valvethrough the second section further comprises providing a pushing member;and using the pushing member to apply a force to the crimped prostheticvalve to push the crimped prosthetic valve through the second section ofthe loading apparatus.

In another embodiment, an apparatus for delivering a prosthetic valvethrough the vasculature of a patient is provided. The apparatuscomprises a main catheter, a balloon catheter, a valve covering member,and a compressing member. The main catheter comprises a distal section.The balloon catheter comprises an elongated shaft and a balloon memberconnected to a distal end portion of the shaft, with the balloon memberhaving an external surface configured to receive a crimped prostheticvalve. The valve covering member extends from the distal section of themain catheter and over at least a portion of the balloon member. Thevalve covering member is compressible to apply a compressive force tothe prosthetic valve when the prosthetic is crimped on the balloonmember. The compressing member is configured to compress at least aportion of the valve covering member.

In specific implementations, the compressing member comprises a nosepiece, the nose piece being disposed distal to the balloon member andbeing configured to receive at least a portion of a distal end of thevalve covering member. In other specific implementations, the nose pieceis coupled to a distal end of the balloon member. In other specificimplementations, the portion of the distal end of the valve coveringmember that is received by the nose piece has a smaller inner diameterthan a portion of the valve covering member that is not received by thenose piece. In other specific implementations, the portion of the distalend of the valve covering member that is received by the nose piececomprises at least one slit or notch.

In other specific implementations, the compressing member comprises anouter covering member. The outer covering member has an elongated shaftand is movable longitudinally relative to the valve covering member. Theouter covering member is configured to have a smaller inner diameterthan an outer diameter of the valve covering member, such that when theouter covering member extends over the valve covering member, the valvecovering member is compressed to a smaller inner diameter. In otherspecific implementations, the valve covering member is adhered to thedistal section of the elongated shaft of the main catheter. In otherspecific implementations, the valve covering member is integrally formedwith the distal section of the elongated shaft of the main catheter.

In another embodiment, a method of loading a crimped prosthetic valveinto a lumen of a delivery system is provided. The method comprisesproviding a main catheter with an elongated shaft; providing a ballooncatheter with an elongated shaft and a balloon member disposed at adistal end of the elongated shaft; crimping a prosthetic valve on theballoon member; providing a valve covering member, the valve coveringmember being configured to extend at least from a distal end of the maincatheter to a distal end of the balloon member, the valve coveringmember having at least one slit or notch at a distal portion of thevalve covering member; covering the crimped prosthetic valve with thevalve covering member; crimping at least a portion of the valve coveringmember to a smaller profile, the portion of the valve covering memberthat is crimped covering at least a portion of the crimped prostheticvalve during the act of crimping; providing an outer covering member,the outer covering member having an elongated shaft; and moving theouter covering member to extend over the portion of the valve coveringmember that covers the crimped prosthetic valve, the outer coveringmember being sized to apply a compressive force to the valve coveringmember. In specific implementations, at least a part of the act ofmoving the outer covering member over the valve covering member occurswhile the valve covering member is loaded into a crimping device.

The foregoing and other features and advantages of the invention willbecome more apparent from the following detailed description, whichproceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an exemplary embodiment of a balloon expandableprosthetic heart valve.

FIG. 1B is a simplified side view of a balloon expandable prostheticheart valve delivery system that is configured to support and deliverthe balloon expandable prosthetic heart valve in FIG. 1A to a targetarea inside a patient's body.

FIG. 2 is an illustration of a crimping device used to mount abioprosthesis to a balloon catheter.

FIG. 3A is a illustration of a valve recoil inhibitor in accordance withan embodiment disclosed herein.

FIGS. 3B and 3C are exemplary illustrations of a valve recoil inhibitorpositioned on a delivery system in accordance with an embodimentdisclosed herein.

FIGS. 4A and 4B are illustrations of an embodiment disclosed herein.

FIGS. 5A-5D are illustrations of an embodiment disclosed herein.

FIG. 6 is a illustration of an embodiment disclosed herein.

FIGS. 7A and 7B are side views of an integrated bioprosthesis/deliverysystem loading system in accordance with an embodiment disclosed herein.

FIG. 7C is a cross sectional view of the integratedbioprosthesis/delivery system loading system of FIG. 7A in accordancewith an embodiment disclosed herein.

FIGS. 8A-8G show an exemplary process for loading a prosthesis assemblyinto delivery system in accordance with an embodiment disclosed herein.

FIG. 8H is a cross sectional view of an integratedbioprosthesis/delivery system in accordance with an embodiment disclosedherein.

FIG. 9 is an illustration of a loading tool in accordance with anembodiment disclosed herein.

FIG. 10 is an illustration of a loading tool in accordance with anembodiment disclosed herein.

FIG. 11A is an illustration of a loading tool in accordance with anembodiment disclosed herein.

FIG. 11B is an illustration of a loading tool and an integratedbioprosthesis/delivery system in accordance with an embodiment disclosedherein.

FIG. 12 is an illustration of a loading tool in accordance with anembodiment disclosed herein.

DETAILED DESCRIPTION

The following description is exemplary in nature and is not intended tolimit the scope, applicability, or configuration of the invention in anyway. Various changes to the described embodiment may be made in thefunction and arrangement of the elements described herein withoutdeparting from the scope of the invention.

FIG. 1A illustrates an exemplary embodiment of a balloon expandableprosthetic heart valve 100 (hereinafter, “bioprosthesis 100”).Bioprosthesis 100 includes an implantable structure 102 (also referredto herein as a stent or support frame), a flexible membrane 104, and amembrane support 106. Implantable structure 102 is expandable from afirst reduced diameter to a second enlarged diameter, and has a flowpath along a longitudinal axis. Implantable structure 102 generally maybe a tubular framework, such as a stent as shown in the illustratedexample, which primarily anchors bioprosthesis 100 within or adjacentthe annulus of the defective valve in the heart. Implantable structure102 provides stability and helps prevent bioprosthesis 100 frommigrating after it has been implanted.

Flexible membrane 104 is positionable in the flow path for permittingflow in a first direction, and substantially resisting flow in a seconddirection. In one preferred configuration, the flexible membrane can beformed from tissue, such as, for example, bovine pericardial tissue, ora suitable biocompatible, synthetic material such as those described inU.S. Pat. No. 6,730,118, which is incorporated herein by reference.Membrane support 106 is positionable in the flow path and affixed, suchas by suture, to implantable structure 102. Membrane support 106 cancomprise a fabric skirt that surrounds the lower portion of the membrane104 to reinforce the connection between the membrane 104 and the frame102.

Prior to implantation, bioprosthesis 100 is carefully mounted andcrimped onto a catheter assembly (delivery assembly) 108 (hereinafter,“assembly 108”), which can include a delivery catheter 110 and a ballooncatheter with an elongated shaft 116 and a balloon member 112 (FIG. 1B).The balloon catheter can have an inner lumen that is in fluidcommunication with the balloon member 112 and a fluid pressurizingdevice (not shown). During inflation of the balloon member 112, fluidpasses from the fluid pressurizing device to the balloon member 112 andthe balloon member is inflated with a controlled volume of fluid (e.g.,saline/contrast).

Delivery catheter 110 can be used to deliver and deploy the appropriatesize bioprosthesis 100. Delivery catheter 110 can be a guide catheter orflex catheter that is configured to be selectively steerable or bendableto assist the surgeon in guiding the delivery assembly 108 through thepatient's vasculature. In one embodiment, delivery catheter 110 advancesbioprosthesis 100 through a sheath over a guidewire and tracksbioprosthesis 100 through the aortic arch. Delivery catheter 110 alsoaids in crossing, and positioning bioprosthesis 100 within the nativevalve. Delivery catheter 110 can include a tapered nose cone 118 mountedat the distal end of a respective catheter shaft 119, which allowsassembly 108 to cross the native valve easily. In one exemplaryoperation, bioprosthesis 100 and assembly 108 are inserted into thefemoral artery and delivered to the site of the native stenotic aorticvalve. Bioprosthesis 100 is positioned and deployed across the stenoticnative valve. The balloon delivery system is then removed. An exemplarybioprosthesis 100 designed for transfemoral implantation in patientswith severe aortic stenosis (AS) is the SAPIEN transcatheter heart valvemodel 9000TFX available from Edwards Lifesciences Corporation, Irvine,Calif., the assignee of the present invention. An exemplary catheterassembly 108 designed to deliver bioprosthesis 100 is the RETROFLEX IIcatheter assembly also available from Edwards Lifesciences Corporation,Irvine, Calif. The bioprosthesis can be implanted in a retrogradeapproach where the bioprosthesis, mounted in a crimped state at thedistal end of a delivery apparatus, is introduced into the body via thefemoral artery and advanced through the aortic arch to the heart, asfurther described in U.S. Patent Publication No. 2008/0065011, which isincorporated herein by reference.

Although the operation described above is a performed with an elongatecatheter in a percutaneous transfemoral procedure, it should beunderstood that the present invention may also be used with a shortercatheter assembly in a minimally-invasive surgical transapical procedurefor treating a defective aortic valve. In the transapical procedure, thebioprosthesis is preferably advanced into the heart through a smallincision formed between two ribs and through an incision formed in theapex of the heart. Although the transapical procedure is generallyconsidered a more invasive approach as compared with the percutaneoustransfemoral procedure, the direct line of access used in thetransapical procedure provides the physician with greater degree ofcontrol during advancement and deployment of the bioprosthesis.

With reference now to FIG. 2, a crimping device 200 is illustrated whichmay be used to mount bioprosthesis 100 to the catheter assembly 108. Inone embodiment, crimping device 200 is a single-use non-patientcontacting, compression device that symmetrically reduces the overalldiameter of bioprosthesis 100 from its expanded size to its collapsed(mounted) size, effectively mounting bioprosthesis 100 to its deliveryballoon catheter 112. Crimping device 200 includes a housing 202 and acompression mechanism 204. Compression mechanism 204 is closed by meansof a handle 206 located on housing 202. Crimping device 200 is alsoequipped with two measuring gauges: a crimp gauge 208 to verify that thebioprosthesis/balloon assembly has been suitably collapsed, and aballoon gauge 210 to verify the bioprosthesis/balloon assembly catheterdiameter when inflated. Further details relating to a crimping devicecan be found in U.S. Patent Publication No. 2007/0056346, which isincorporated herein by reference.

As mentioned above, despite the most careful and firm crimping ofbioprosthesis 100 and balloon catheter 112 to closely conform to theoverall desired profile of the catheter unexpanded balloon 112 andunderlying inflatable tube components, there is a certain amount of“recoil” of implantable structure 102 (hereinafter, “stent 102”) or atendency of stent 102 to slightly open from a desired hypotheticalminimum crimped diameter. This tendency of stent 102 to open or recoilslightly when crimped on balloon catheter 112 has been characterized as“recoil.” The actual minimum diameter achievable for fully crimped stent102 on balloon catheter 112 is referred to as delivery diameter D1 (FIG.1B).

In a first embodiment shown in FIGS. 3A-3C, a valve recoil adapter 300is illustrated which may be used to counteract stent recoil bycompressing a crimped valve to the delivery diameter D1 of bioprosthesis100 as it is inserted into a delivery device. Valve recoil adapter 300includes a first portion with a large open end 304 and second portionwith a crimp diameter portion 302. A frusto-conical transitional portion305 extends between the first and second portions. Crimp diameterportion 302 may be variably sized to any desired delivery diameter.

In operation, as shown in FIGS. 3A, 3B and 3C, after crimpingbioprosthesis 100 onto balloon catheter 112 to form a prosthesisassembly 114 (using, for example, crimping device 200), prosthesisassembly 114 is inserted into large open end 304 of valve recoil adapter300 until it can be force fit into crimp diameter portion 302. The crimpdiameter portion 302 counter acts any recoil that stent 102 onprosthesis assembly 114 has experienced after crimping by radiallycompressing prosthesis assembly 114 back to its desired deliverydiameter D1. In the absence of valve recoil adapter 300, the deliverydiameter D1 is dependent on random recoil that the material experiencesafter the crimping process. Valve recoil adapter 300 allows thepractitioner to control the delivery diameter D1 of prosthesis assembly114.

Referring to FIG. 3B, in one embodiment, valve recoil adapter 300 can beconfigured for use with another delivery system, i.e., loader device310. For the purposes of this application, the term “delivery system”refers to any apparatus or structure that has a lumen or other openinginto which a prosthesis assembly can be received and includes, forexample, a catheter, a loader device, and an introducer sheath. Loaderdevice 310 has a lumen into which a prosthesis assembly can be loaded.Loader device 310 can be attached to an introducer sheath (not shown) byclips 312. The distal end of the introducer sheath is inserted into apatient's vessel (e.g., the femoral artery) over a guide wire andreceives a delivery assembly, which is inserted through the introducersheath and into the vessel, as known in the art. Valve recoil adapter300 is desirably configured to extend into the lumen of the loaderdevice 310 and attach to a proximal end of loader device 310. The methodof attachment could include, for example, screwing threaded portionstogether, clipping, snap fit, etc. Typically, the introducer sheath islong enough to extend through the portion of the delivery path havingthe smallest diameter. As the prosthesis assembly 114 is insertedthrough the recoil adapter 300, it is compressed to diameter D1 forinsertion through the loader 310 and introducer sheath. Accordingly, theoverall cross-sectional profile of the introducer sheath can be reducedto minimize trauma to the patient.

Referring to FIG. 3C, in another embodiment, valve recoil adapter 300can be configured for use with a delivery catheter 110. Deliverycatheter 110 can be configured to receive the prosthesis assembly 114within an enlarged portion 120 of catheter 110. Valve recoil adapter 300can be secured to enlarged portion 120 between the prosthesis assembly114 and the enlarged portion 120. Portion 302 desirably extends intoenlarged portion 120. If desired, portion 302 can be secured to theenlarged portion 120 by configuring the recoil adapter 300 and enlargedportion 120 with mating threaded portions or sizing portion 302 so itfits tightly into the enlarged portion 120.

After the valve 100 is crimped onto balloon member 112, the prosthesisassembly 114 is moved longitudinally relative to the delivery catheter110, such as by retracting shaft 116, to position the prosthesisassembly 114 within the enlarged portion 120. Since valve recoil adapter300 is positioned between the prosthesis assembly 114 and the enlargedportion 120, the prosthesis assembly 114 must pass through valve recoiladapter 300 before entering the enlarged portion 120 of the deliverycatheter 110. As the prosthesis assembly 114 passes through the crimpdiameter portion 302, the outer diameter of crimped valve 100 ismaintained at (or reduced to) the inner diameter of the crimp diameterportion 302. Once the prosthesis assembly 114 is positioned within theenlarged portion 120, the valve recoil adapter 300 is removed from theassembly. If desired, nose cone 118 can have a hollow section which canbe moved proximally to cover the distal end portion of the balloonmember 112 and/or valve 100.

If it is desirable to remove the valve recoil adapter 300 from thedelivery assembly, such as in the embodiment shown in FIG. 3C, it may bedesirable to form the valve recoil adapter in two or more pieces. Forexample, valve recoil adapter 300 can be formed so that it is split inhalf longitudinally, with those two halves being configured to fittogether to form a single part. The two (or more) parts can attach toone another by various mechanical means, such as by a snap-fitconnection. Alternatively, valve recoil adapter 300 can form its cone(or funnel) shape by having a single piece of material that is rolled upinto a cone shape. Thus, upon unraveling, the valve recoil adapter 300can be removed from the assembly.

Referring now to FIGS. 4A-B, in a second embodiment the elongated shaft116 of the balloon catheter may be inserted through an elongated shaftof catheter 110 with tip mobility, such as Edwards' RETROFLEX IIcatheter available from Edwards Lifesciences Corporation. Bioprosthesis100 may be crimped on balloon member 112 using crimping device 200 (FIG.2) to form prosthesis assembly 114 having, for example, a deliverydiameter D1 (FIG. 1B).

As shown in FIG. 4A, prosthesis assembly 114 can be inserted or coveredwith over tube 402, which substantially maintains prosthesis assembly114 at delivery diameter D1 and prevents stent 102 from recoiling.Another function of over tube 402 is to provide protection to the bloodvessel from the bare stent of bioprosthesis 100.

Over tube 402 can be secured at its proximal end to the inner surface ofdelivery catheter 110. At its distal end, over tube 402 can betemporarily attached to a tip 406. Tip 406 also can be mounted on (orotherwise attached to) a distal end of balloon member 112.Alternatively, tip 406 can have a separate elongated shaft and can bemoveable in the longitudinal direction independently of the elongatedshaft of the balloon member.

Tip 406 can have a smaller diameter than the diameter of the elongatedshaft of the delivery catheter 110. In addition, tip 406 can haveextending portions 410, which are configured to capture and hold adistal portion 412 of over tube 402. Over tube 402 is desirably formedof a material that can be compressed to a smaller diameter at its distalend, so that the distal portion 412 can be inserted and held within theextending portions 410. Accordingly, as shown in FIG. 4A, when thedistal portion 412 of over tube 402 is secured at a smaller diameter bytip 406, an inward pressure (a compressive force) is applied by the overtube 402 to prosthesis assembly 114, which reduces and/or maintains thediameter of the prosthesis assembly at the desired delivery diameter.

When the prosthesis assembly 114 is in position for deployment at thetreatment site, over tube 402 can be moved proximally and the prosthesisassembly 114 can be uncovered. As shown in FIG. 4B, by moving the shaftof the delivery catheter 110 in the proximal direction, as shown byarrow 414, distal portions 412 of over tube 402 are no longer capturedby extending portions 410, and over tube 402 returns to its natural(uncompressed) diameter. Once over tube 402 returns to its naturaldiameter, prosthesis assembly 114 can be fully uncovered by continuingto move the shaft of the delivery catheter 110 in the proximaldirection.

In another embodiment, shown in FIGS. 5A-5D, the distal portion 412 ofover tube 402 can be formed with slits (or cuts) 404. Slits 404 permitthe over tube 402 to form a tapered portion 408 that extends into and iscaptured by tip 406. The tapered portion 408 can extend approximatelyfrom bioprosthesis 100 to tip 406 of balloon catheter 112.

FIG. 5A shows the prosthesis assembly 114 positioned within over tube402. Distal portion 412 of over tube 402 is positioned so that at leasta portion of it is captured within tip 406, causing over tube 402 to beradially compressed and to have a diameter that is smaller than itsnatural, uncompressed diameter.

Referring now to FIG. 5B, over tube 402 can be attached to the elongatedshaft of delivery catheter 110. Over tube 402 can be attached in avariety of manners to the distal end of the elongated shaft of deliverycatheter 110. For example, over tube 402 can be attached to an innersurface of the distal end of the elongated shaft of the deliverycatheter 110 (as shown in FIG. 5A) or it can be attached to an outersurface of the elongated shaft of the delivery catheter 110. Over tube402 can be moved back (proximally) relative to prosthesis assembly 114by moving the elongated shaft of the delivery catheter 110 (to whichover tube 402 is attached) proximal relative to the prosthesis assembly114. When over tube 402 is pulled back, the distal portion 412 of theover tube 402 is released from the tip 406 and the distal portion 412 ofover tube 402 expands to its natural, uncompressed diameter.

Slits 404 allow over tube 402 to flare open and allows an easyextraction of prosthesis assembly 114 with substantially no friction.Slits 404 can be of any desired length. In addition, as shown in FIG.5B, slits 404 can be formed as triangular cuts in the distal portion 412of over tube 402. By forming the slits 404 as triangular cuts, thedistal portion 412 can be more easily reduced to a smaller diameter whencaptured by the tip 406. As shown in FIGS. 5C and 5D, over tube 402 canbe pulled back further so that prosthesis assembly 114 is completelyexposed, and balloon member 112 may be then inflated freely.

In an alternative embodiment, shown in FIG. 6, before crimpingbioprosthesis 100 onto balloon member 112, balloon member 112 can bepassed through an introducer sheath 602 having a relatively smalldiameter. As discussed above, introducer sheaths typically extend intothe smallest portion of the patient's vasculature. Accordingly, it canbe desirable to crimp bioprosthesis after passing it through theintroducer sheath. Once bioprosthesis 100 is mounted onto ballooncatheter 112 to form prosthesis assembly 114, over tube 402 can beplaced over prosthesis assembly 114.

In this embodiment, prosthesis assembly 114 with over tube 402 is loadedin front of introducer sheath 602. Since over tube 402 is relativelythin when compared to the thickness of introducer sheath 602, the totalsize of the delivery diameter is reduced. Tapered portion 408 can have asmooth, bullet like shape, allows prosthesis assembly 114 to beatraumatically advanced to the heart valve and passed through thecalcified valve.

Over tube 402 may be formed from any suitable materials, such asplastics and metals, such as Nitinol and stainless steel. Over tube 402can be secured to the distal end of the shaft of the delivery catheterby a variety of methods. For example, over tube 402 can be secured onthe inside or outside surface of the shaft of the delivery catheter.Alternatively, over tube 402 can extend longitudinally with the deliverycatheter 110 (either inside or outside the shaft of the deliverycatheter) and can be capable of independent longitudinal movementrelative to the shaft of the delivery catheter 110.

FIGS. 7A and 7B illustrate another embodiment of an integratedbioprosthesis/delivery system 700. In one configuration, delivery system700 includes a moveable cover 702 and a slit tube 704 in a first or openposition. Moveable cover 702 is positioned over slit tube 704 in atelescoping arrangement. Slit tube 704 is disposed at least partiallywithin cover 702 and is longitudinally moveable relative to cover 702.Slit tube 704 includes at least one slit 706, and defines a tubularspace sized to receive prosthesis assembly 114, including bioprosthesis100 and balloon catheter 112.

In operation, prosthesis assembly 114 is positioned within slit tube704, while moveable cover 702 is in the retracted position (FIG. 7A).Moveable cover 702 is sized so that sliding moveable cover 702 over slittube 704 in the distal direction (as shown by arrow 710) applies acompression force on prosthesis assembly 114. In this manner, prosthesisassembly 114 is surrounded and squeezed by slit tube 704 and moveablecover 702 so that the entire device has a small profile and is ready forinsertion into a body lumen. Sliding moveable cover 702 back relative toslit tube 704 (in the direction opposite arrow 710) allows slit tube 704to open and release the compression force from prosthesis assembly 114.

FIG. 7C is a cross-sectional view of delivery system 700 showing anelongated shaft 708 (e.g., a shaft of a flex or guide catheter)positioned within slit tube 704. Elongated shaft 708 can be formed withan enlarged section 709 that is configured to receive a portion of theprosthesis assembly 114 when it is pulled back into slit tube 704. Forclarity, FIG. 7C is shown in partial cross section with the prosthesisassembly 114 removed. Operationally, as moveable cover 702 is movedforward (distally) relative to slit tube 704, cover 702 slides over slittube 704 and shaft 708, and compresses both slit tube 704 and shaft 708.As shaft 708 is compressed, it captures and holds prosthesis assembly114 during delivery of prosthesis assembly 114 through the patient'svasculature. Slit tube 704 is desirably adhered to shaft 708, using anadhesive or other securing means.

Slit tube 704 can extend longitudinally to an area just proximal to thedistal end of the elongated shaft 708. An inner surface of slit tube 704can be adhered to an external surface of elongated shaft 708. In such aconfiguration, movement of elongated shaft 708 effects movement of slittube 704, and slit tube 704 can be positioned by moving elongated shaft708. Alternatively, slit tube 704 can extend substantially the length ofelongated shaft 708 and can be moveable relative to (and independent of)elongated shaft 708.

FIGS. 8A-8H show an exemplary process for loading prosthesis assembly114 into delivery system 700. As shown in FIG. 8A, bioprosthesis 100 andballoon 112 are positioned in crimper 200. Next, bioprosthesis 100 iscrimped over balloon catheter 112, forming prosthesis assembly 114 (FIG.8B). Crimper 200 can be opened and prosthesis assembly 114 can be placedinto slit tube 704 by sliding slit tube 704 over prosthesis assembly114. The slits 706 formed in slit tube 704 permit slit tube 704 toexpand (flare out) at its distal end when outward pressure is applied tothe area of slit tube 704 near slits 706. FIG. 8C shows slit tube 704partially covering prosthesis assembly 114 and FIG. 8D shows slit tube704 completely covering prosthesis assembly 114.

Slit tube 704, including prosthesis assembly 114 positioned therein, canbe placed back into crimper 200 and the prosthesis assembly 114 can becrimped again, this time inside of slit tube 704 (FIG. 8E). With theprosthesis assembly 114 and a portion of the slit tube 704 still in thecrimper 200, moveable cover 702 can be slid forward over a protrudingpart of slit tube 704 (FIG. 8F). Crimper 200 can be opened and moveablecover 702 can be slid forward over the remainder of slit tube 704 untilmoveable cover 702 reaches nose tip 802. By partially extending moveablecover 702 over slit tube 704 prior to releasing slit tube 704 from thecrimper 200, moveable cover 702 can resist recoil of the crimped valve100, at least to the extent that moveable cover 702 extends over aportion of the crimped valve 100. By moving the moveable cover 702completely over the slit tube 704, moveable cover 702 exerts compressiveforces against slit tube 704 and keeps slit tube 704 closed overprosthesis assembly 114 (FIG. 8G).

FIG. 8H is a cross sectional view of an exemplary delivery system 700including prosthesis assembly 114 in accordance with an embodiment.Cover 702 abuts nose tip 804 at its distal end and. At its proximal end,cover 702 has a transition portion 712, where the diameter of cover 702is reduced until it reaches a smaller diameter portion 716. Slit tube704 extends from a distal end of the valve 100 to the transition portion712. As shown in FIG. 8H, slit tube 704 can be a separate element thatis adhered to (or otherwise coupled to) a widened section 714 ofelongated shaft 708. Alternatively, slit tube 704 can be integral withthe elongated shaft 708. Nose cone (nose piece) 802 provides a taperedsurface for atraumatic tracking of the delivery assembly through thepatient's vasculature. Nose cone 802 abuts cover 702 and can have arecessed portion so that cover 702 and nose cone 802 can combine to forma uniform outer surface.

In operation, once prosthesis assembly 114 is encapsulated in deliverysystem 700, the delivery system may be inserted into a body lumen, andstabilized at a target position. Next, moveable cover 702 may be slidback (proximally) relative to the prosthesis assembly 114. Once moveablecover 702 is slid back and the compressive forces of moveable cover 702removed from slit tube 704, slit tube 704 and prosthesis assembly 114can be easily repositioned relative to one another. Thus, slit tube 704can be moved off of the prosthesis assembly 114 by pushing prosthesisassembly 114 forward (distally) or pulling slit tube 704 back(proximally), or both. Balloon member 112 can be inflated to deliverbioprosthesis 100 at the target position. After deployment ofbioprosthesis 100, balloon member 112 can be deflated. Moveable cover702 can be slid back (distally) over the deflated balloon member 112 andslit tube 704, and delivery system 700 can be retracted from thevasculature of the patient.

FIG. 9 is an illustration of yet another embodiment. In this embodimenta loading tool 1002 can assist the loading of prosthesis assembly 114into the distal end of the delivery system 700 after the prosthesisassembly 114 is withdrawn from crimper 200. Loading tool 1002 cancomprise a first section 1010 and a pushing member 1016. First section1010 can have a hollow section with an internal diameter that variesfrom a larger diameter section 1012 to a smaller diameter section 1014.By positioning prosthesis assembly 114 into the larger diameter 1012section and pulling or pushing prosthesis assembly 114 through thesmaller diameter 1014 section of section 1010, the outer diameter (orradial profile) of prosthesis assembly 114 can be reduced.

Pushing member 1016 can have a handle portion 1017 and one or moreextending members 1018 that extend from an end of pushing member 1016.In operation, prosthesis assembly 114 can be positioned at (or into) thelarger diameter section 1012. Prosthesis assembly 114 can then be pushedfurther into first section 1010 until it reaches and passes through thesmaller diameter section 1014. Prosthesis assembly 114 can be pushed (orurged) through the first section 1010 by extending members 1018, whichcan be configured to extend into the hollow section of first section1010 and to contact a distal end of bioprosthesis 100.

Extending members 1018 can be formed in a variety of shapes. Extendingmembers 1018 can be hollow (as shown in FIG. 10B) or solid. In addition,extending members 1018 can be formed with a number of slits that resultin the extending member having a plurality of annularly spaced fingersections (as shown in FIG. 11B). Extending members can also be formed ofa variety of materials. Desirably, extending members 1018 are configuredso they can collapse to smaller outer diameter, in order to be able topush the prosthesis assembly 114 all the way into the smaller diametersection of the first section 1010. The extending members can becollapsible by forming the extending members with, for example, aflexible material, a plurality of slits, or both.

Desirably, extending members 1018 are sized and configured to follow theinner surface of hollow sections 1012 and 1014, so that extendingmembers 1018 engage the prosthesis assembly 114 at its widest point.Because the implantable structure 102 of bioprosthesis 100 generallyforms the widest area of the crimped prosthesis assembly 114, by formingextending members 1018 so they extend along the inner surface of thehollow sections (rather than through an inner area of the hollowsection), the extending members 1018 can be configured to push againstthe implantable structure 102 (or frame), which is generally the mostdurable and tear resistant portion of bioprosthesis 100.

First section 1010 can also be attached to crimper 200 (as shown in FIG.10) and prosthesis assembly 114 can be crimped to a small diameter andthen the crimped prosthesis assembly 114 can be pulled back through theattached first section 1010 to further reduce the profile of theprosthesis assembly 114 or to maintain the desired crimped profile whiletransferring the prosthesis assembly 114 from the crimper 200 to thedelivery device.

As shown in FIG. 10, first section 1010 can include be attached tocrimper 200 to assist in loading prosthesis assembly 114 into deliverysystem 700. Prosthesis assembly 114 may be loaded into a slit tube 704and cover 702 of a delivery system immediately after the prosthesisassembly 114 is crimped by crimper 200. Here, the distal end of thedelivery system can be compressed by placing the distal end in thecrimper jaws. Crimper 200 may be closed to a diameter that is smallerthan the inner diameter of moveable cover 702, allowing prosthesisassembly 114 to be small enough in diameter to slide easily intomoveable cover 702. By placing prosthesis assembly 114 into the largerdiameter 1012 section and pulling or pushing prosthesis assembly 114through the smaller diameter 1014 section of first section 1010, theouter diameter (or radial profile) of prosthesis assembly 114 can bereduced.

FIGS. 11A and 11B are illustrations of a loading tool 1102 with a firstsection 1010 and a pushing member 1016. In this embodiment, a taperedguide serves as an introduction channel into delivery system 700.Prosthesis assembly 114 can be pushed by a pushing member (slit tubularpusher) 1016 through tapered channel 1106 into moveable cover 702.Passing prosthesis assembly 114 through the tapered channel (hollowsection) 1106 of Loading tool 1102 causes the prosthesis assembly 114 tohave a reduced radial profile. Pushing member (slit tubular pusher) 1106can be configured to be able to pass through both the larger diametersection 1012 and the smaller diameter section 1014, which allows thepushing member 1016 to be able to apply lateral pressure to prosthesisassembly 114 throughout the tapered channel 1106.

Loading tool 1102 can have a delivery system receiving area 1105, whichis configured to receive a distal end of the delivery system. Forexample, moveable cover 702 can extend into the delivery systemreceiving area 1105 so that the prosthesis assembly 114 can be passeddirectly into the desired position on the delivery system after passingthrough the smaller diameter section 1014. In this manner, moveablecover 702 can be configured to compress around prosthesis assembly 114as it is placed into moveable cover 702, thereby preventing theprosthesis assembly 114 from expanding (or recoiling) back to a largerdiameter. A force F1 can be applied to the distal end of the deliverysystem to maintain the delivery system within the first section 1010while the pushing member 1016 exerts a force F2 in the oppositedirection. Desirably, a lip 1110 (shown in FIG. 11A) can be formed by adifferential between the diameters of the delivery system receiving area1105 and the smaller diameter section 1014. Lip 1110 is provided to abutthe distal end of the delivery system when it is positioned in thedelivery system receiving area 1105. The lip 1110 can help to maintainthe delivery system in the desired position while loading the prosthesisassembly 114 through first section 1010. Slits can be provided on thepushing member 1016 to form fingers (extending members) 1108. The slitspermit the fingers 1018 to contract to a smaller diameter, allowingfingers 1018 to more easily follow the inner surface of the taperedchannel 1106 from the larger diameter section 1012 to the smallerdiameter section 1014.

FIG. 12 is an illustration of a loading device that is configured toclamp prosthesis assembly 114 between two clamp portions 1202, 1204 tofacilitate the loading of prosthesis assembly 114 into delivery system700. Clamp portion 1202 has a plurality of pins 1206 that protrude fromthe surface of clamp portion 1202. Clamp portion 1204 has a plurality ofopenings 1207 that are configured to receive pins 1206. Channel 1210 canbe formed by an opening on both clamp portions 1202, 1204 that extendsfrom side of the loading device to the other. Channel 1210 can have adelivery system receiving area 1211, a prosthesis assembly receivingarea 1209, and a pushing member receiving area 1213. FIG. 12 showsbioprosthesis 100 (without the balloon member for purposes ofillustration) positioned in the prosthesis assembly receiving area 1209of clamp portion 1202.

In this embodiment, prosthesis assembly 114 is positioned between fourpins 1206 that protrude out of the clamp portion 1202 adjacent theprosthesis assembly receiving area 1209. A distal end of a deliverydevice can be positioned at one end of channel 1210, in the deliverysystem receiving area 1211. Clamp portion 1204 can then be positioned sothat the openings 1207 mate with each of the protruding pins 1206 onface 1202 and the two faces can be pushed together. As clamp portion1204 is pushed against clamp portion 1202, compressive forces urgeprosthesis assembly 114 into a profile with a smaller diameter.Desirably, prosthesis assembly is urged into an oval shape. Prosthesisassembly 114 can then be pushed into an opening in a distal end of thedelivery system, which has about the same diameter as the compressedprosthesis assembly 114. To push the prosthesis assembly 114 into thedelivery system, a pushing member 1016 with extending members 1018 (suchas those described above) can be pushed into the pushing memberreceiving area 1213 and up against the prosthesis assembly 114. Byapplying lateral pressure towards the delivery system with the pushingmember, the prosthesis assembly 114 can be pushed into position withinthe distal end of the delivery system.

Channel 1210 can be formed in a variety of other configurations. Forexample, channel 1210 can be formed with one or more tapered sections sothat the prosthesis assembly 114 can be reduced in diameter as it passesfrom a larger diameter section to a smaller diameter section (asdiscussed in more detail in other embodiments.) The number andorientation of pins and openings can also vary. For example, the loadingdevice could have pins on both surfaces, and openings on both surfaces.Alternatively, another system besides pins could be used to align thetwo surfaces with one another.

The invention has been disclosed in an illustrative manner. Accordingly,the terminology employed throughout should be read in an exemplaryrather than a limiting manner. Although minor modifications of theinvention will occur to those of ordinary skill in the art, it shall beunderstood that what is intended to be circumscribed within the scope ofthe patent warranted hereon are all such embodiments that reasonablyfall within the scope of the advancement to the art hereby contributed,and that that scope shall not be restricted, except in light of theappended claims and their equivalents.

1. A valve loading apparatus for loading a crimped prosthetic valve intoa lumen of a delivery system, the valve loading apparatus comprising: afirst portion, the first portion being configured to receive a crimpedprosthetic valve; a second portion configured to be coupled to a distalend of the delivery system; and a transitional portion, wherein theapparatus has an opening that passes through the first, second, andtransitional portions, the opening having a first diameter at the firstportion and a second diameter at the second portion, the first diameterbeing larger than the second diameter, the transitional portion having atransitional diameter that varies from the first diameter to the seconddiameter, and wherein when the crimped valve is passed through theopening of the loading apparatus and into the lumen of the deliverysystem, the crimped valve is radially compressed from a larger diameterto a smaller diameter.
 2. The valve loading apparatus of claim 1, thesecond portion having a third diameter section, the third diameter beinglarger than the second diameter, wherein the transition from the seconddiameter to the third diameter forms a lip, the lip being configured toabut the distal end of the delivery system.
 3. The valve loadingapparatus of claim 1, further comprising a first clamp portion and asecond clamp portion, the first and second clamp portions beingseparable from one another, wherein the first clamp portion forms a partof each of the first, second, and transitional portions, and the secondclamp portion forms the remainder of the first, second, and transitionalportions.
 4. The valve loading apparatus of claim 1, further comprisinga pushing member, the pushing member comprising a handle portion and oneor more extending portions, the extending portions having a hollowcentral area and being sized to extend into the opening of the valveloading apparatus to urge the crimped prosthetic valve through theopening of the valve loading apparatus.
 5. The valve loading apparatusof claim 4, wherein the extending portions of the pushing membercomprise two or more annularly spaced finger members.
 6. A method ofloading a crimped prosthetic valve into a lumen of a delivery system,the method comprising: crimping a prosthetic valve on a balloon memberof a balloon catheter; providing a loading apparatus, the loadingapparatus having a first section and a second section, the first sectionhaving a first diameter and the second section having a second diameter,wherein the second diameter is smaller than the first diameter;introducing the crimped prosthetic valve into the first section, whereinat the time of introduction into the first section, the crimpedprosthetic valve has a diameter greater than the second diameter; andpassing the crimped prosthetic valve through the second section and intothe lumen of the delivery system, the crimped prosthetic valve exitingthe second section with the crimped prosthetic valve having a diameterthat is equal to or less than the second diameter.
 7. The method ofclaim 6, further comprising: coupling the second section of the loadingapparatus to a distal end of the delivery system.
 8. The method of claim6, further comprising: passing the balloon member through an introducersheath prior to prior to crimping the prosthetic valve on the balloonmember.
 9. The method of claim 6, wherein the act of passing the crimpedprosthetic valve through the second section further comprises: providinga pushing member; and using the pushing member to apply a force to thecrimped prosthetic valve to push the crimped prosthetic valve throughthe second section of the loading apparatus.
 10. An apparatus fordelivering a prosthetic valve through the vasculature of a patientcomprising: a main catheter, the main catheter comprising a distalsection; a balloon catheter comprising an elongated shaft and a balloonmember connected to a distal end portion of the shaft, the balloonmember having an external surface configured to receive a crimpedprosthetic valve; a valve covering member extending from the distalsection of the main catheter and over at least a portion of the balloonmember, the valve covering member being compressible to apply acompressive force to the prosthetic valve when the prosthetic is crimpedon the balloon member; and a compressing member configured to compressat least a portion of the valve covering member.
 11. The apparatus ofclaim 10, wherein the compressing member comprises a nose piece, thenose piece being disposed distal to the balloon member and beingconfigured to receive at least a portion of a distal end of the valvecovering member.
 12. The apparatus of claim 11, wherein the nose pieceis coupled to a distal end of the balloon member.
 13. The apparatus ofclaim 11, wherein the portion of the distal end of the valve coveringmember that is received by the nose piece has a smaller inner diameterthan a portion of the valve covering member that is not received by thenose piece.
 14. The apparatus of claim 11, wherein the portion of thedistal end of the valve covering member that is received by the nosepiece comprises at least one slit or notch.
 15. The apparatus of claim10, wherein the compressing member comprises an outer covering member,the outer covering member having an elongated shaft and being movablelongitudinally relative to the valve covering member, the outer coveringmember being configured to have a smaller inner diameter than an outerdiameter of the valve covering member, such that when the outer coveringmember extends over the valve covering member, the valve covering memberis compressed to a smaller inner diameter.
 16. The apparatus of claim10, wherein the valve covering member is adhered to the distal sectionof the main catheter.
 17. The apparatus of claim 10, wherein the valvecovering member is integrally formed with the distal section of the maincatheter.
 18. A method of loading a crimped prosthetic valve into alumen of a delivery system, the method comprising: providing a maincatheter with an elongated shaft; providing a balloon catheter with anelongated shaft and a balloon member disposed at a distal end of theelongated shaft; crimping a prosthetic valve on the balloon member;providing a valve covering member, the valve covering member beingconfigured to extend at least from a distal end of the main catheter toa distal end of the balloon member, the valve covering member having atleast one slit or notch at a distal portion of the valve coveringmember; covering the crimped prosthetic valve with the valve coveringmember; crimping at least a portion of the valve covering member to asmaller profile, the portion of the valve covering member that iscrimped covering at least a portion of the crimped prosthetic valveduring the act of crimping; providing an outer covering member, theouter covering member having an elongated shaft; and moving the outercovering member to extend over the portion of the valve covering memberthat covers the crimped prosthetic valve, the outer covering memberbeing sized to apply a compressive force to the valve covering member.19. The method of claim 17, wherein at least a part of the act of movingthe outer covering member over the valve covering member occurs whilethe valve covering member is loaded into a crimping device.